The overall goal of the Ischemic SCOR Program at Iowa is to perform coordinated interdisciplinary research aimed at elucidating basic mechanisms responsible for the regulation of the coronary circulation. Another primary goal of the Ischemic SCOR Program is to investigate several clinically important questions that will be immediately applicable to the care of patients with Ischemic heart disease. Four of the nine projects in the Ischemic SCOR (Physiological Significance of Coronary Obstruction; New Echocardiographic Approaches; Studies of Acute Ischemia in Patients; and Modulation of Ischemic Induced Arrhythmias by Autonomic Tone) are primarily oriented toward clinical problems of immediate concern. The remaining five projects in the SCOR (Coronary Smooth Muscle; Coronary Endothelium; Coronary Microvasculature; Coronary Collateral Circulation; and Central Control of the Coronary Circulation) focus on basic research questions. Acquisition of new basic information concerning regulation of the coronary circulation will eventually enhance our understanding of mechanisms that are important in the pathogenesis of myocardial ischemia. Ultimately this approach will lead to improvements in the care of patients with ischemic heart disease. The nine projects in the Ischemic SCOR will be supported by five core facilities: an Image Processing Laboratory; Anatomy/Pathology Core; Biostatistics Core; Nuclear Imaging Core and an Administrative Core. The research team consists of 25 investigators from six departments, Medicine, Surgery, Pharmacology, Preventative Medicine/Biostatistics; Radiology and Engineering. The Ischemic SCOR will complement existing large research programs currently under the aegis of the Cardiovascular Center at the University of Iowa.